JSFiddle - React, Tailwind, and code Playground

by jonathanmh

HTML

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Hello World</title>
    <style>
      article {
        max-width: 38rem;
        padding: 2rem;
        margin: auto;
        font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
      }
    </style>
  </head>
  <body>
    <article>
      <h1>Hello World of Web Components</h1>
      <p>This is a web components demo! Now let's go:</p>
      <!-- DANGER -->
      <!-- WEB COMPONENTS -->
      <!-- BEYOND THIS POINT -->
      <hello-world></hello-world>
    </article>
  </body>
</html>

JavaScript

// ES6 class
      class HelloWorld extends HTMLParagraphElement {
        // constructor is called when the element is displayed
        constructor() {
          super();
          // create a shadow dom
          const shadow = this.attachShadow({ mode: "closed" });
          // create a span element
          const text = document.createElement("span");
          // set the content to 'Hello World'
          text.textContent = 'Hello World';
          // insert our created element into our shadow DOM, causing it to appear
          shadow.appendChild(text);
        }
      }

      // make sure that the <hello-world></hello-world>
      // or simply <hello-world /> is recognised as this element
      customElements.define("hello-world", HelloWorld, { extends: "p" });